Hardening-machine.



C. C. JACKMAN & R. S. SQUIRE.

HARDENING MACHINE.

APPLICATION .FlLED OCT. 22. I917- 1,299,949, Patented Apr. 8,1919.

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CHESTERC. JAGKMAN AND RAYMOND S. SQUIRE, OF STRINGFTELD, MASSACHUSETTS,ASSIGNORS TO MASSACHUSETTS SAW WORKS, 011 SPRINGFIELD,MASSACHUSETTS,

A TRUST ASSOCIATION OF MASSACHUSETTS.

HARDENING-MAGHINE.

Specification of Letters Patent.

Patented Apr. s, .1919.

I Application filed October 22, 1917. Seria1'No.197,85G.

To all whom it may concern:

Be it known that we, CHESTER JACKMAN and RAYMOND S. S UIRE, citizens ofthe United States of America, residing at Springfield, in the county ofHampden and State of Massachusetts, have invented certain new and usefulImprovements in Hardening- Machines, of which the following is aspecification.

This invention relates to improvements i machines for automaticallyhardening steel articles, such as hacksaw blades, for example. Theinvention, furthermore,'relates to improvements in machines of the typedisclosed in our copending application Serial No. 148,250, filedFebruary 12, 1917.

In such machines, articles, as hack-saw blades, are connected intocontinuous chain form and passed successively through a heating and aquenching means, the latter generally involving the use of oil. It isobvi- 'ously desirable to subject the articles to the action of thequenching means as soon as possible after their exit from the heating.

means. To obtain this desirableresult, the quenching and heating meansare necessarily located adjacent one another, and, by reason of suchproximity, much difficulty has been hithertoexperienced from theignitionofthe oil. A further source of difliculty is experi enced from thesplash of the'oil used for quenching purposes against the incoming chainof red hot saws. If such oil first strikes a heated surface and is thendeflected therefrom against the heated saws, lgnition is liable tooccur. The present invention is to be distinguished from others dealingwith the prevention of the oil following back along the saw chain intothe furnace, and it is recognized-that various means have been proposedto overcome this difiiculty, as evidenced by the prior art. For example,various arrangements have been used to prevent the oil from followingback along the saws into the furnaces, as. shields and devicesyieldingly forced against the articles. How

such heated oil as encounters the red hot saws in a splash or spray. Thedanger from the ignition of even small quantities of oil hes 1n thepossibility of communication with 'the main body of oil, and, where thequenching means consists of an oil bath, it'will be apparent thataserious 'conflagration may result.

According to one feature of the invention, the chain ofarti'clesispassed successively through a heating and a quenching means and a tankis associated with the latter to receive oil therefrom, which tank has ajacket'ed wall adjacent the exit of the heating means to receive acooling medium, whereby the oil falling into said tank and againstitswalls may be cooled sufficiently to prevent its ignition by the incomingheated chain of articles. j

According to another feature of the invention, the quenching means takesthe form of a relativ ly large body of oil through which the heatedarticles travel in a straight line at a substantial distance below thesurface to prevent flashing of the oil, and such oil as passes fromtheoil bath through the entrance orifice of'the oil bath enters a tankinterposed between the oil bath and the heating means and the wall ofthe tank adjacent the latter is cooled by the circulation of a suitablemedium therein, so that such oil as enters the tank is cooledsufiiciently to pre vent its ignition by the incoming heated articles.

Other features of the invention will appear in the following descriptionand in the illustrative embodiment of the invention in the accompanyingdrawings, in which- Figure 1 is a fragmentary elevational View, partlyin section, of a hardening machine embodying' the invention; and

Fig. 2 is a cross-sectional view taken on the line 22 of'Fig. 1. I

Referring to these drawings, the furnace is indicated in conventionalform at 5, and 6 is the tubular exit mouth of the furnace. Any suitabletype of furnace may be used as desired, and the invention is independentof the specific type of furnace employed. Detailed description andillustration of the furnace are thought unnecessary to an un derstandingof the invention as furnaces are now well known in the art.

Closely adjacent the exit 6 of the furnace is a tank 7 having arelatively large co1n partment 8 to contain a quenching medium, as oil,and relatively small compartments 9 and- 10at each end thereof. "The endwall of tank 7 adjacent the tube 6 is provided with a jacket 11 throughwhich a suitable the furnace 5 and compartments 8, 9, and 10.

.Themeansfor supporting, guiding, and propelling the chain of articles15 have not been-illustratedinasmuch as they are un- -necessary to anunderstanding of the invention by those skilled in the art and any suit-.able supporting, guiding and propelling .means may beemployed asdesired.

noil issupplied to compartment 8 by an inlet pipe 17 from asuitablesource of supply by any'suitable means, and the inflow of oil is-such asto maintain the surface of the oil asubstantial distance above the lineof travel of the articles 15. Necessarily,

v since various-sizes'of saws are to be handled,

the openings 14 cannot readily closely fit any given size of saw, andthereforeoil from compartment 8 will flow through openings 'l l-intothecompartments 9 and 10. Such oil as enters the latter compartments may bereturned from pipes 18 and 19 to the source of supply, sothat no actualloss of oil .results and an advantageous circulation of oil. incompartment 8 is obtained.

vThe oil level in compartment 8 is main- :tained at such a level thatthe heated saws plunge into the oil at such a depth below the Isurfacethat flashing of the oil does not readily occur. As to the ignition ofsuch oil as enters into compartment 9,-thejacket 11 is provided. .Thiscooling jacket keeps the compartment 9-relatively cool, while otherwiseit would be heated to a considerable degree since it is practicallycontiguous to the exit tube 6, which becomes red hot while the furnaceis in operation. Without'the jacket .11, therefore, the oil enteringcompartment 9 would strike a highly heated surface and would frequent-lyigniteandcause a possible conflagration by igniting the large body ofoil'in compartmentB. The jacket 11 obviates-this difiiculty inasmuchas'it keeps the compartment 9- cool and counteracts the effect of thefurnace. The oil enters co1npartment 9 in afrelativelysmall stream fromcompartment 8, and the volume of this strea1n is such that .thetemperature of vthe oil may be readilylowered by the jacket 11toa'deg'ree sufiicient to prevent its ignition.

The: :chief difficulty encountered heretofore has been not so'much fromthe en- "surface and, when deflected from this sur face tothe red hotsaw chain, was, on ac count of its temperature, quite likely to igniteand cause trouble. With the described arrangement, however, all the oilentering compartment 9 is cooled, and particularly such oil as strikesthe wall of jacket 11 is cooled to a considerable degree, and the dangerof oil ignition is reduced to a minimum.

The invention has been disclosed in an embodiment at present Ipreferred, for the purposes of illustration, but the scope of theinvention is defined by the appended claims rather than by the foregoingdescription.

What we claim is--.

1. In a hardening machine, a heating means and a liquid quenching meansthroughwhich a chain of articles may be successively passed, a'tankassociated" with the quenching means to receive liquid overflowing fromthe latter, and a jacketed wall provided forsaid tank adjacent the exit.of the heating means, through which walla cooling medium may becirculated to cool the quenching liquid in said tanksufficiently toprevent its ignition.

2. In a hardening machine, a heating means and a tank through which achain of articles may be successively passed in a straight line, acompartment in said tank containing a body of an ignitible quenchingliquid, the surface of which is asubstantial distance above the path oftravel of said chain, an orifice in said compartment to permit theentrance of the chain, a'compartment in the tank between the quenchingliquidcompartment and the exit ofthe ,heating means to receiveth'eliquid flowing from :the former through its orifice, and meanstocool the liquid entering into the second'compartment.

3. In a hardening machine, afurnace, a

tank, one end of which is closely adjacent.

the exit end of-the furnace, a jacketed wall in said end of the tankthrough which a cooling medium may be circulated, a compartment in saidtank .to contain anignitible' quenching liquid spaced from the jacketedend leaving a second, compartment, and an orifice provided in thejacketed end and in each wall'of'the first of articles may be passed ina straight line from said furnace at a substantial discompartmentthrough which orifices a chain 12 so that the liquid fiowing'froni thefirst compartment to the second compartment t through the orifice iscooled by the jacketed wall su'fiiciently to prevent its ignition.

4. In a machine of the character described, a heating means and aquenching wall of said tank adjacent to the heating 10 means beinghollow and closed to communication with the tank so that a coolingmedium'may be circulated Within said wall to cool the latterindependently of the quenching means for the purposes set forth. 15

CHESTER C. JACKMAN. RAYMOND S. SQUIRE.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patentl, Washington, D. 0.

